Answer:
5. The correct answer would be an option A. ova
Note: I assume that all the samples are of human origin.
DNA (deoxyribonucleic acid) content of somatic cells of humans consists of 46 chromosomes or 23 pairs of chromosomes. Gametes (sperm or ova) are haploid cells produced by the process of meiosis and contain half the number of chromosomes found in parent cell. Hence, they contain 23 chromosomes.
6. The correct answer would be an option J.
Sperm formation or spermatogenesis is the process by which spermatozoa (haploid gamete) is produced from germ cell with the help of meiotic division.
Meiosis results in the formation of four haploid (n) cells from single diploid (2n) parent cell. Here, 2n is given as 8 so, n would be equal to 4.
Meiosis I results in the formation of two secondary spermatocyte cells (both haploid or 4 chromosomes in this case) from single primary spermatocyte (diploid or 8 chromosome in this case).
Both the secondary spermatocytes undergo meiosis II to produce 4 spermatids (each haploid or 4 chromosome in this case). Spermatids differentiate and mature into spermatozoa.
The component of DNA that became the source of this information is : the base
The backbone of our DNA carries four type of bases which each could contain unique sequences
These unique sequences of the four bases are the one that encodes the information.
Pollen tube growth is one of the most fascinating—and essential—phenomena in the life cycle of flowering plants. After a compatible interaction between pollen grains and the stigma surface, the pollen germinates and forms the pollen tube, which grows through the stigma, style, and transmitting tract to deliver the sperm cells to the ovule."
2) Although pollens of many species germinate in simple aqueous media, stigmas do not provide satisfactory sites for the germination of most foreign pollen... Stigmas not only provide the proper conditions for the germination of pollen from their particular species, they actively inhibit the germination of pollen of many unrelated species.
<span>F- allele for freckles
f- </span><span>allele without freckles
1) The man is heterozygote and has freckles, its indicating that the allele for freckles is dominant.
A cross between him and a woman who is also </span><span>heterozygote: Ff x Ff
it would result in the following probabilities:
- 1/4 - homozygote with freckles: FF
- 2/4 - </span><span>heterozygote with freckles: Ff
- 1/4- </span><span>homozygote without freckles:ff
Their son would have a probability of 75% of being born with freckles.
2) The cross resulted in this probabilities:
</span><span><span>- 1/4 - homozygote with freckles: FF
- 2/4 - </span><span>heterozygote with freckles: Ff
- 1/4- </span><span>homozygote without freckles:ff
So, the chance of being born heterozygote for this gene is 2/4, which is the same as half (50%).
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